The ornamental design for an acousticfeedbackheadset, as shown and described.
FIG. 1 is a front perspective view of the acoustic feedback headset design;
FIG. 2 is a front perspective view of the acoustic feedback headset design with the acoustic feedback tubing in an operative position;
FIG. 3 is a front elevation view of the acoustic feedback headset design;
FIG. 4 is a rear elevation view of the acoustic feedback headset design;
FIG. 5 is a bottom plan view of the acoustic feedback headset design;
FIG. 6 is a bottom plan view of the acoustic feedback headset design with the acoustic feedback tubing in an operative position;
FIG. 7 is a top plan view of the acoustic feedback headset design;
FIG. 8 is a top plan view of the acoustic feedback headset design with the acoustic feedback tubing in an operative position;
FIG. 9 is a left side elevation view of the acoustic feedback headset design; and,
FIG. 10 is a right side elevation view of the acoustic feedback headset design.
The broken line disclosures shown in the Figures of the acoustic feedback headset design are for illustrative purposes only and forms no part of the claimed design.